Drill-chuck.



F. E. BOCORSELSKI.

DRILL CHUCK.

APPLICATION FILED N0v.22. 1911.

L'YAQK Patented Sept. 10, 1918* INVEN'I'OFZ ill BOCOBSELSKI, OF RICHMOND, 'vmo DRILL-CHUCK.

To all whom it may concern:

Be it known that I, FRANK SKI, ofRichmond, in the county of Henrico and State of Virginia, have invented a certain new and useful Improvement in Drill- Chucks, of which improvement the following is a specification. My invention relates to appliances for centering, holding, and driving drills or other cutting tools, and its object is to provide a simple and inexpensive device for positively driving straight shankcutting tools, which will enable broken drills of every description to be utilized .without waste, thereby efi'ecting great economy in the cost of high speed tool steel.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a view, partly in elevation and partly in longitudinal central section, of a drill chuck and inserted drill, illustrating an ap plication of my lnvention; Fig. 2, a similar view, taken at a right angle to Fig. 1; Fig. 3, a transverse section, the upper half of which is taken on the line a: a" of Fig 1, and the lower half on the line y 4 thereof; Fig. 4, a similar section, on the line a z of Fig. 2; Fig. 5, a longitudinal central section through the driving bushing or collet; Fig. 6, a view in elevation thereof, taken at a right angle to Fig. 5; Fig. 7, an end view, as seen from the right; Fig. 8, a view, partly in elevation and partly in longitudinal central section of a drill chuck and inserted drill, illustrating a structural modification, and, Fig. 9, a transverse section through the same, on the line to w of Fig. 8.

In the practice of my invention, referring descriptively to the specific embodiment thereof which is herein exemplified, I provide a cylindrical socket member, 1, which is adapted to be connected to the spindle of the machine by which it is rotated, either by having a threaded bore, 1, formed at one of its ends, or by being provided with a suitable shank. The socket member is ,bored out conically at its opposite end, to

receive a correspondingly turned driving bushing or collet, 2, and a screw is cut on its periphery for a portion of 1ts length from said end, for the connection of an internally threaded collar, 5. A transverse drift pin hole, 1", is formed in the socket member, adjacent to the inner end of its conical bore.

E. Booonsnu thread, 1,

Specification of Letters Patent. P t ee t, 1Q, 1913,

5 Application filed Rovember 22, 1917. serial No. 208,329.

bore, 2, and a, rectangular transverse slot,

2", extends from the opposite end of the bore to the smaller end of the collet, at a right angle to the slots, 2.

The cutting tool, 3, which is to be carried and driven by the socket, and which, in this instance, is shown as a twist drill, is turned, adjacent to one of its ends, to fit in the cylindrical bore of the collet, and. a flat tang, 3, is formed upon it, extending from the cylindrically turned portion to the adjacent end. The tang, 3 fits neatly in the transverse slot, 2, of the collet.

Rotation is positively imparted to the collet, 2, and inserted cutting tool, 3, from the socket member, 1, by a tapered or conical driving pin, 4, which is fixed transversely in the socket member and is flattened at its inner end, which enters and engages the slot, 2 of the collet. By screwing the collar, 5, to a tight bearing on the socket member and against the larger end of the collet, 2, the latter is contracted so as to firmly grip the tool, 3, thereon.

Figs.- 8 and 9 illustrate a modification of structural detail in which the smaller end of the collet, 2, is turned to tapered or conical form, and a drift pin, 6, having a correspondingly turned bearing face, 6, on its inner end, is formed or fixed on a stem, 7 which is fitted transversely in the socket member, 1, adjacent to the inner end of the collet, 2. The bearing face of the drift pin is normally held out of contact with the end of the collet by a spring, 8, which surrounds the stem, 7 and wh'enit is desired to remove the collet from the socket member, the collar,

5 is detached, and the collet loosened and pushed out of its fit in the socket, by driving on the outer end of the drift pin, upon to clamp it in the bore of the socket mem her, and on the tool, with force propertionate to the extent or increase of such pressure. The tool is held firmly in the collet by the engagement of its tang with the longitudinal slot thereof, and, with the collet, is positively rotated by the engagement of the driving pin with said slot.

The practical advantages of my invention will be obvious to those skilled 1n machine shop operation, in the particulars of the simplicity and inexpensiveness of the appliance; its capability of use on the spindles of various kinds of machines for providing a positive driving mechanism which practically forms part of the machine; and the great economy which is efl'ected in its application, by rendering straight shank drills available at a much lower cost, and byntilizing broken drills. of every description, which, in view of the cost of high speedsteel, efi'ects a saving, which, in large shops, will amount to thousands of dollars per year. l

I claim as my invention and desire to secure by Letters Patent:

A drill chuck the body of which is adapt- .ed to be mounted on-the spindle of a machine tool and has a cylindrical bore in its rear end and a conical bore in its front end, said body having also a transverse taper cylindrical hole at right angles to said taper hole and intersecting the junction of said conical and cylindrical bores, a split collet or bushing fitting said conlcal bore and having a slot for a portion of its length from its rear end, said end being chamfered a hole intersecting said conical bore and a ofi, a driving pin fitted in said taper hole and having a flattened end to enga e in-said slot, a drift .pin slidably mounts in said cylindrical hole and having a conical end to engage the chamfered end of said collet, a spring ressing said drift pin outwardly and a co lar screw-threaded on the front A. W0 HIGH. 

